Clamp for forms containing moldable material



June 4, 1957 srr'ro 2,794,467

CLAMP FOR FORMS CONTAINING MOLDABLE MATERIAL Filed Jan. 12, 1955 INVENTOR.

PHILIP N. SITTQN ATTORNEYS CLAMP FOR FORMS CONTAINING MOLDABLE MATERIAL Philip N. Sitton, Dayton, Ohio, assignor to The Philip Sitton Septic Tank Company, Dayton, Ohio, a corporation of Ohio Application January 12, 1955, Serial No. 481,332

4 Claims. (Cl. 144291) The present invention relates to fastening devices adapted for use in securing together sectional forms used in connection with the pouring of semi-fluid substances such as concrete in the building of various structures.

The invention is particularly adaptable for use in connection with clamping parts together and in which the holding or tension rod of the clamp is held in strict longitudinal stress. In particular, the approved clamp finds considerable use in the manufacture of concrete septic tanks which are formed in molded sections clamped together to receive the concrete and in which the sections are released and opened to expose the hardened concrete'mass.

Clamps heretofore employed for the purpose mentioned may take the form of the device shown in my Patent'No. 2,674,284. These clamps, of which several are used along the extreme end joints of a two-section mold, are satisfactory in operation, but it has been found that during constant use over long periods of time the holding bar.

of the clamp which is curved, tends to straighten out under severe tension. This may cause the camming action at the operating lever to become less and thereby lose some of its clamping effect.

The primary object of the invention is to provide a clamp of the pressure lever type in which the tension element remains in a rectilinear condition in order to oifer the maximum resistance to distortion of the element during the clamping operation. V

Another object is to provide a clamping device in which the tightening effect is obtained by a crank arm action which causes pressure against a camming pivot.

Still another object is to provide a clamping device of rugged design and formed of rotary cam surfaces and levers, which levers in their clamping position remain in a straight line or rectilinear shape.

A further object is to provide a fastening device suitable for clamping the ends of form sections together, and in which the elements of the device comprise a rectilinear rod and a crank arm of different lengths so that as the arm is rotated about its center, a clamping pressure is applied by the rod against the ends of the form sections.

Another object is to provide a fastening device suitable for clamping the ends of the form sections together, and

in which-the stationary clamping member of the device. sets squarely against one of the form sections and remains in this squarely set position throughout the entire clamping operation.

Still another object is to provide a fastening device suitable for clamping the ends of form sections together, said device comprising a pivoted leverand a crank arm, and in which the pivoted lever, when operated, causes the crank arm to exert a clamping pressure at the posi-= tion of the abutting form sections.

A still further object is to provide a fasteningfdevice:

adapted for clamping sectional forms together and in which the operated parts of the clamp are separable from the elements which locate the device with; respect -t'o the sectional forms; I a 'L atent Patented June 4, 1957 It hasalso been found that whenever the clamping tension is exercised through a curved bar or rod as, for example, of the type shown in my patent, supra, there may be a tendency for the gripping end of the bar to move slightly with respect to the clamp parts. This is due to the fact that the pulling or clamping force is not exercised exactly at right angles to the joint between the clamped members. Accordingly, another object of the invention is to provide a clamp suitable for fastening concrete form sections together and in which the clamping efiect is exercised in a direction exactly normal to the joint between the clamped parts so as to eliminate the tendency for the gripping end of the bar to move with respect to the clamped parts.

The final object of the invention is to provide a clamping device formed of a tension rod, swivelly mounted on a lever, together with an adjustable stop to control the amount of maximum tension that can be applied to the rod during the clamping operation.

Other objects and features will be apparent as the specification is perused in connection with the accompanying drawings, in which:

1 Figure 1 is a perspective and elevational view of the end portions of the outer form walls used in the manufacture of a concrete septic tank, together with one of the improved clamping devices for holding the end portions together;

Figure 2 is a perspective elevational view of the end portions of the inner and outer form walls and'showing a number of the improved clampingdevices'for fasten ing the ends of the outer form portions together;

Figure 3 represents a plan View of the clamping device with the intermediate portions of the outer molding form and the clamp support elements in section in order to show the relation between the clamp and its supporting elements with respect to the molding form;

Figure 4 is an elevational view of the improved clamp ing device and the outer concrete form, together with the clamp supporting elements in section;

I Figure 5 is a detail view illustrating the clamping elements which are temporarily removed from their supports and depicting the ease with which these elements can be moved apart from their supports so as to be interchangeable with one another at the clamping position; and

Figure 6 is a diagrammatic depiction of the relative movements between the various rods and levers of the.

to the concrete molding operation to form a joint 2..

It will be understood that septic tanks are usually made in polygonal form out of reinforced concrete. The tanks are made in two, three or four sections high with suitable grouting or grooves at the edges to maintain the sections strictly in alignment on top of one another.

Each section of the tank is peripherally complete and the thickness of the tank walls is regulated by form sections which are shown more completely in Fig. 2, and of which a portion of the end panels of the outer form section has been illustrated in Fig. 1.

As shown in Fig. 2, the inner form wall, generally designated at 3, is constituted of a number of planar sides and given the polygonal configuration by means of brace bars 4 which extend diagonally across a number of the panels of the inner form, together with transverse brace bars 5 extending between the long brace bar .4 and each of the panel portions 6.

The inner form wall is perimetrically complete except that it extends. for only one-half the length of the tank,

there being provided a similar inner form wall for the other section of the tank which meets with the firstmentioned form wall at the mid-point of the tank.

There is an outer form wall formed of flat panels or portions 7 which conform to the same shape as .the inner form wall but are uniformly spaced from the latter at the requisite distance to receive the concrete. This outer form wall has a joint 2 at each end as the wall is complete fromone end to the other. The portions 7 of the outer wall as well as the adjacent portions 6 of the inner wall are constituted of sheet metal, and in order to conform the outer wall portion 7 to the inner wall portion 6 and thus insure a uniform thickness of .concrete throughout the entire length of the tank, brace bars 8 are connected to the portion 7 and these brace :bars terminate ina U-shaped truss 9 which extends the entire length of the outer wall form. V V A truss bar 10 is bolted at ll tothe truss 9 and a bridge 12 spaces the truss bar from the truss at the middle of the outer form. Thus, by tightening the bolts 11, inward pressure can be applied to the truss 9 and .communicated through the brace bars 8.to the individual panel portions 7 to assure a uniform spacingbetween the inner and outer form walls.

When the inner and the outer form-wall sections are set up for receiving the poured cement, it -is necessary that the joint -.2 between the adjacent panels 7 at the ends of the form he completely tight so as not to lose any concrete at the joint 2. In order to align the end panels 7 with one another and thus to assure complete contact between these portions at the .joint .2, I mayemploy .one or more sets of aligning guides 13, as shown more clearly in Figure 1. To support these guides, there is an angle iron bracket '14 welded along one side to each of the panel portions 7.

The inner edges of these angle brackets are spaced slightly apart atthe position so as not to interfere with the closeness of contact at the joint 2 between the adjacent outer form sections. The inner ends and a part of one of the edges of the guides 13 are welded to the inner surfaces of the angle bracket 14so that the outer ends of these guides extend considerably beyond the bracket to which it is secured and is in such position that they actually touch the outer edge of the bracket on which they rest when the joint 2 has been tightly closed in a mannenwhich will be described hereinafter. v

Thus, these guides serve to align the contactingsurfaces of the end form sections 7 preparatory to clamping these sections together. As-shown in Fig. 2, ,severalpairs of these aligning guides may be used, depending on the width or height of the .end portions 7.

The present invention relates more especially to the clamp for bringingthe end portions 7 together atthe joint 2 so as to leave no opening at the joint through which concrete may escape, although it will be understood that the improved clamp may be used in connection with any structure, the parts of which must be brought together in a tight fit. As shown in Fig. 2, three such improved clamps, generally designated at 16, are shown, placed on opposite sides of the aligning guides 13.

The clamp consists essentially of a rod 17 whichis received at one end by a slot 18 in the angle iron,'that end of-the rod being threaded as indicated at19. Asupport 20 is welded, as indicated at'21 (Fig. v3) to theend portion 7 and, in addition, at its outer edge is welded to one of the arms of the. angle iron, as indicated at 22. As shown, this support extends outwardly in a direction parallel to the angle iron on the other end portion '7 so that. the rod 17 can extend at right-angles therewith during the clamping operation described here-M inafter. Thus, a side-wise strain is avoided at the ,posi:

tion of the support 20. There is a slot in the support.

20 to permit the threaded end of the rod 17 to extend; therethrough.

' The hreaded end 1901? .thered reeeivesanut .fiwhieh extending web of the angle iron 14 in order looselyto accommodate the rod.

There is a U-shaped member 29 welded, as indicated at 30 in Fig. 1, to the right-hand end portion 7, the inner edge 31 of this member being welded to the web of the bracket onopposite sides of the slot 28. There is a pair'of pins 32 extending inwardly from the walls of the U-shaped member 29, these pins serving as a bearing surface for the inner end of a lever 33. The latter terminates at one end in a forked member :34 which is provided with semi-circular recesses .35 at the extreme end, these recesses being of a size as to swivelly fit around the pins 32. The pin 27 which carries the eyelet 26 of the rod 17 extends across the two arms of the fork portion 34.

There is a screw 36 which passes through the solid or base portion 37 of the fork member 34, the purpose of this screw being .to limit the downward movement of the lever .33 when the latter is placed in clamping position, as will be explained hereinafter. be provided on the screw 36 and which bears against the base portion of the fork member 34 in order to prevent further movement of the screw 36 after the .latter has been adjusted to proper position.

Assuming that the nut 23 and the screw 36 have been properly adjusted, which is .done on a trial and error basis, the hand lever33 is moved inwardly against the end portion 7 and it will be observed that during this movement the rod 17 will have been caused to ride inwardly iilto the U-shaped member 29 until the end of the screw 36 contacts the bottom of that member. The fork member 34 will have been caused to swivel about the pins 32' so that when the rod or bar 1 7 will have assumed a position approximately at right-angles to the support 20 as seen in Fig. 3, the nut 23 will be squarely seated in its curved recess and a strong tension pull will be exercised on .the rod 17 by the camming action produced between the pivots 32 and the pin 27. This strong tension pull on the rod 17 will produce a tremendous clamping force atthe joint 2 so that the end portions 7 of the outersectional form are rigidly brought together at the joint 2. It be noted in Fig. 3 that in the clamped position of, the ,lever 33, the rod 17 just clears the metal portions on each side of the joint 2 and the space 15. Greater or less clamping effects may be effected by tightening or' loosening the screw 36 after the lock nut 38 has been first loosened until the pressure required to' give the clamping effectis well within the strength of a workman.

In .order to loosen the clamp, it is merely necessary to pull the lever 33 outwardly away from its adjacent form,

section 7, at whichtime it will be noted that the rod 17 and the lever 33 may be completely withdrawn intact from the support 20..and the vU-shaped member'29. This bodily removal of these elements has been indicated in Fig. Sand the advantage is that these elements as :a whole can be used at any other position along the joint 2 when.

suitable brackets 20, the U-shaped member 29 and the necessary vslots are provided. Since these elements 17 and 33, together with the nuts 23, 25 and the screw 36, are .bodily removable from the joint, it may be desirable toprovide a retaining chain 39, stapled at 40, in the lever The pivots. 32am indicated as a circle :in this Figure, as:

is also the pin 27. The lever 33 has also been indicated A lock nut 38 may a line 33 extending at an angle with respect to the rod or line 17.

When the lever is depressed, i. e. actually pressed inwardly toward the end form section 7, it causes the pivot 27 to move about the center 23 along an are A which is determined by the radius B representing the distance between the nut 23 and the pin 27. However, the fact that the fork member 34 tries to rotate about the pivots 32 along an are C representing a radius D as the distance between the pivots and the pin, causes the pin 27 to be subjected to two curvatures of movement, namely A and C, with the result that a camming action is produced between the pivots 32 and the forked portion 34 which results in tension being applied to the rod 17 This tension can be increased up to a certain point by regulating the position of the nut 23 on the rod 17 and by also adjusting the screw 36 which represents a stop element. It will be noted that when tension is applied to the rod 17 by operating the lever 33, the rod 17 remains rectilinear in shape so that the tension is strictly longitudinal of the rod. The latter therefore produces a square abutting pressure at the nut 23 and the latter merely moves in and out of its recess 24a and does not slide about the recess. Consequently, the pull exercised by the rod 17 is always firm and there is no sliding action at the nut 23.

It will be understood that various modifications and arrangements in structure could be made without departing from the spirit of my invention and, accordingly, I desire to comprehend such modifications and substitutions of equivalents :as may be considered to come within the scope of the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a concrete wall form having a plurality of wall sections in angularly disposed relationship to each other around the periphery of said form, a fastening device for connecting the end pair of wall sections together along their edges, a pair of brackets extending outwardly from each end pair of walls, notches in each pair of brackets in line with one another, a rectilinear rod extending through said notches, one end of said rod being threaded, :a nut on said threaded end and bearing against the outer surface of the immediately adjacent bracket, a U-shaped member secured to the outer surface of the other of said brackets, a pair of pins extending inwardly from opposite sides of said U-shaped member, a forked member adapted to be received by said U-shaped member, the ends of the forked member having recesses which bear against said pair of pins, a pin extending across the walls of said forked member, said rod at the end opposite from said nut terminating in an eyelet which rotatably surrounds said last-mentioned pin, and means for rotating said forked member about its pin to cause a camming action at the bearing between the recesses and said pair of pins whereby the rod is placed in rectilinear tension and clamping pressure is applied between the end pair of walls.

2. In a concrete wall form having a plurality of wall sections in angularly disposed relationship to each other around the periphery of said form, a fastening device for connecting the end pair of wall sections together along their edges, a pair of brackets extending outwardly from each end pair of said walls, transverse slot means in each of said brackets and a rectilinear rod removably positioned in said slot means, said rod having a threaded portion on one end receiving nut means for frictional engagement with one of said brackets, said nut means having a curved face at the point of engagement with said bracket and a curved recess about the slot directly adjacent the curved surface of said nut means to receive the nut, an eyelet on the opposite end of said rod, a U-shaped member secured to the other of said angle-iron members, a forked member contained within said U-shaped member, a pin extending across said forked member surrounded by the eyelet portion of said rod, said U-shaped member having a pair of oppositely disposed pins extending toward one another from opposite walls of the member, said forked member having recesses at one end bearing against the last-mentioned pins, the end of the forked member opposite from said pins terminating in an operating handle for rotating the member about all of said pins and thereby to exert a pulling effect on a rod when the curved portion of the nut on the rod remains in the curved recess of the bracket.

3. In a concrete wall form having a plurality of wall sections around the periphery of said form, fastening means for connecting a pair of angularly related wall sections together along their edges, said fastening means comprising a pair of brackets, one secured to each of said pair of wall sections and extending outwardly at right angles therefrom, a support member secured at one of its ends to one of said wall sections and at the other end to the bracket of said one wall section, said support member extending in a direction substantially parallel to the bracket of the other of said wall sections, notches in the ends of each bracket and the support member in line with one another, a rectilinear rod extending through said notches in a direction normal to the support member, one end of said rod being threaded, a nut on said threaded end and bearing against said support member, a U-shaped member secured to the outer surface of the bracket on the other of said wall sections, a pair of pins extending inwardly from opposite sides of said U-shaped member, a forked member adapted to be received by said U-shaped member, the ends of the forked member having open recesses which bear against said pair of pins, a pin extending across the walls of said forked member, said rod at the end opposite from said nut terminating in an eyelet which rotatably surrounds said last mentioned pin, whereby the forked member, the rod and its eyelet and the nut on the threaded end of the rod are completely detachable from the U-shaped member, but when in position and the forked member is caused to rotate about its pin with the ends of the forked member bearing against said pair of pins, a camming action at the bearing is caused by which the rod is placed in rectilinear tension along the line at right-angles to said support member and clamping pressure is applied between the wall sections.

4. In a concrete wall form having a plurality of wall sections around the periphery'of said form, fastening means for connecting a pair of angularly related wall sections together along their edges, said fastening means comprising a pair of brackets, one secured to each of said pair of wall sections and extending outwardly at right angles therefrom, a support member secured at one of its ends to one of said wall sections and at its other end to the bracket of said one wall section, said support member extending in a direction substantially parallel to the bracket of the other of said wall sections, notches in the ends of said bracket and the support member in line with one another, a rectilinear rod extending through said notches in a direction normal to the support member, an adjustable abutment on said rod adjacent one of said brackets and bearing against said support member and means positioned at the other of said brackets and cooperating therewith for applying tensional stress in said rod while the latter maintains its right angle position with re spect to said support member to cause the brackets to be urged together and thereby apply clamping pressure at said end pair of wall sections.

References Cited in the tile of this patent UNITED STATES PATENTS 830,110 Spencer Sept. 4, 1906 974,983 McHugh Nov. 8, 1910 1,578,340 Miller Mar. 30, 1926 1,792,987 Johnson Feb. 17, 1931 2,489,118 Brinker et al Nov. 22, 1949 2,518,112 Anthony Aug. 8, 1950 2,674,234 ,SittOn Apr. 6, L954; 

